<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
	</head>
	<body>
		
		<script>
			function setCookie(cname,cvalue,exdays){
				var d = new Date();
				d.setTime(d.getTime()+(exdays*24*60*60*1000));
				var expires = "expires=" + d.toString();
				document.cookie = cname + "=" +cvalue + "; " + expires;
			}
			
			function getCookie(cname){
				var name = cname + "=";
				var ca = document.cookie.split(";");
				for(var i = 0;i < ca.length;i++){
					var c = ca[i].trim();
					if(c.indexOf(name)==0)
					   return c.substring(name.length,c.length);
				}
				return "";
			}
			
			function checkCookie(){
				var user = getCookie("username");
				if(user!=""){
					alert("欢迎 " + user + "再次访问");
				}else{
					user = prompt("请输入你的名字: ","");
					if(user!="" && user!=null){
						setCookie("username",user,30);
					}
				}
			}
			checkCookie();
		</script>
	</body>
</html>